#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import re

from impacket.ldap import ldap, ldapasn1
from impacket.ldap.ldap import LDAPSearchError

class CMEModule:
    '''
    Find PKI Enrollment Services in Active Directory and Certificate Templates Names.

    Module by Tobias Neitzel (@qtc_de) and Sam Freeside (@snovvcrash)
    '''
    name = 'adcs'
    description = 'Find PKI Enrollment Services in Active Directory and Certificate Templates Names'
    supported_protocols = ['ldap']
    opsec_safe= True
    multiple_hosts = True

    def options(self, context, module_options):
        '''
        SERVER             PKI Enrollment Server to enumerate templates for. Default is None, use CN name
        '''
        self.context = context
        self.regex = re.compile('(https?://.+)')

        self.server = None
        if module_options and 'SERVER' in module_options:
            self.server = module_options['SERVER']

    def on_login(self, context, connection):
        '''
        On a successful LDAP login we perform a search for all PKI Enrollment Server or Certificate Templates Names.
        '''
        if self.server is None:
            search_filter = '(objectClass=pKIEnrollmentService)'
        else:
            search_filter = '(distinguishedName=CN={},CN=Enrollment Services,CN=Public Key Services,CN=Services,CN=Configuration,'.format(self.server)
            self.context.log.highlight('Using PKI CN: {}'.format(self.server))

        context.log.debug("Starting LDAP search with search filter '{}'".format(search_filter))

        try:
            sc = ldap.SimplePagedResultsControl()
            baseDN_root=",".join(connection.ldapConnection._baseDN.split(",")[-2:])

            if self.server is None:
                resp = connection.ldapConnection.search(searchFilter=search_filter,
                                            attributes=[],
                                            sizeLimit=0, searchControls=[sc],
                                            perRecordCallback=self.process_servers,
                                            searchBase='CN=Configuration,' + baseDN_root)
            else:
                resp = connection.ldapConnection.search(searchFilter=search_filter + baseDN_root + ')',
                                            attributes=['certificateTemplates'],
                                            sizeLimit=0, searchControls=[sc],
                                            perRecordCallback=self.process_templates,
                                            searchBase='CN=Configuration,' + baseDN_root)

        except LDAPSearchError as e:
            context.log.error('Obtained unexpected exception: {}'.format(str(e)))

    def process_servers(self, item):
        '''
        Function that is called to process the items obtain by the LDAP search when listing PKI Enrollment Servers.
        '''
        if not isinstance(item, ldapasn1.SearchResultEntry):
            return

        urls = []
        host_name = None
        cn = None

        try:
            for attribute in item['attributes']:

                

                if str(attribute['type']) == 'dNSHostName':
                    host_name = attribute['vals'][0].asOctets().decode('utf-8')
                if str(attribute['type']) == 'cn':
                    cn = attribute['vals'][0].asOctets().decode('utf-8')

                elif str(attribute['type']) == 'msPKI-Enrollment-Servers':

                    values = attribute['vals']

                    for value in values:

                        value = value.asOctets().decode('utf-8')
                        match = self.regex.search(value)

                        if match:
                            urls.append(match.group(1))

        except Exception as e:
            entry = host_name or 'item'
            self.context.log.error("Skipping {}, cannot process LDAP entry due to error: '{}'".format(entry, str(e)))

        if host_name:
            self.context.log.highlight('Found PKI Enrollment Server: {}'.format(host_name))

        if cn:
            self.context.log.highlight('Found CN: {}'.format(cn))

        for url in urls:
            self.context.log.highlight('Found PKI Enrollment WebService: {}'.format(url))

    def process_templates(self, item):
        '''
        Function that is called to process the items obtain by the LDAP search when listing Certificate Templates Names for a specific PKI Enrollment Server.
        '''
        if not isinstance(item, ldapasn1.SearchResultEntry):
            return

        templates = []
        template_name = None

        try:

            for attribute in item['attributes']:

                if str(attribute['type']) == 'certificateTemplates':
                    for val in attribute['vals']:
                        template_name = val.asOctets().decode('utf-8')
                        templates.append(template_name)

        except Exception as e:
            entry = template_name or 'item'
            self.context.log.error("Skipping {}, cannot process LDAP entry due to error: '{}'".format(entry, str(e)))

        if templates:
            for t in templates:
                self.context.log.highlight('Found Certificate Template: {}'.format(t))